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Dec. 18 1923.

J. W. BUELL CAB SIGNAL AND AUTOMATIC TRAIN CONTROL SYSTEM Filed March 16 Patented Dec. 18, 1923.

UNITED STATES PATENT OFFICE.

JOSEPH WHITMAN BUELL, OF FALLS CHURCH, VIRGINIA; WANDA A. BUELL, EXECU- TRIX OF SAID JOSEPH WHITMAN BUELL, DECEASED, ASSIGNOR TO BUELL SIGNAL AND TRAIN CONTROL COMPANY, INCORPORATED, A CORPORATION OF VIRGINIA,

CAB SIGNAL AND AUTOMATIC TRAIN-CONTROL SYSTEM.

Application filed March 16, 1521.

To aZZ at 710m it may concern Be it known that Josnrn lVHrrMAN BUELL, a citizen of the United States, residing at Falls Church, in the county of Fairfax and State of Virginia, has invented certain new and useful Improvements in a Cab Signal and Automatic TrailrControl System, of which the following is a specification.

This invention relates to a cab signal and automatic train control system of the intermittent contact rail type, in which the cab signal indications and control functions will be automatically produced when the vehicle carried shoe encounters or engages a ramp, to mechanically break a closed circuit, unless automatically prevented by the introduction and operation of an electrical control means provided for said closed circuit under prearranged safety conditions and initiated by the all-rail track circuit condition ahead, and controlled by the contact element or shoe.

One of the principal objects of this in- "ention is to utilize the plan of producing a danger signal and a brake application by dependence on the direct operation of the contact shoe on a ramp for interrupting the control or Working circuit on the carrier, every time an unenergized ramp is encoun tered, thereby providing a valuable selfchecking feature, and for safety signaling to resort to the plan of employing electrical train carried and track connected circuits controlled by the contact elements,to wit, the shoe and ramp, and by an advance all-rail track circuit for the purpose of primarily introducing a preventative low resistance shunt across the control or Working circuit to provide a parallel pathway inside of and in advance of the mechanical breakage of said circuit, Wnereby under safety conditions the Working circuit will remain operatively unaffected and the engineer may proceed with unrestricted speed in the direction of traffic, on a double track line, by reason of a definite, clear or proceed indication.

in carrying out the provisions of a ramp type of system, it has heretofore been deemed necessary, under safety conditions, to insure or depend upon continuous electrical contact of the shoe with the ramp throughout its entire travel thereover.

It is therefore a further object of the Serial No. 452,695.

present invention to provide a relatively short length of ramp, at each signaling and traffic control point, or one sufficient to secure the limited vertical movement of the shoe on the one hand and that will provide for a positive electrical contact of the shoe on the ramp under safety conditions to obtain the required momentary contact on the other hand, thereby dispensing With expensive long ramps and the time consuming feature of lowering the speed of the train in the passage over said long ramps.

It is further an object of the present invention to depend for electric power, upon two engine carried sources of electric energy, which may or may not differ in character and to that end to employ a lOW voltage source of current, as a small storage battery in connection with one portion of the system and limiting it to its proper and economical field of usefulness in supplying current to low volt age signal lamps and electro-magnets, and to utilize on the ramp through a special train carried detecing circuit, a higher voltage current supply, intermittently furnished preferably by the head-light turbo-generator, upon reaching said ramp under clear or safety conditions ahead, and in such an event to make but a momentary demand thereon and in such a manner as to cause an unappreciable fluctuation in the current flowing through the head-light circuit, at night time, thereby reducing with vast economy the cost of the power factor, as distinguished from that. plan of depending upon current collection from respective track sources, at every block interval along the line.

It is a further object of this invention to utilize the track or running rails thereof as a part of the track apparatus for producing signal and control functions on the train, thus requiring the employment of but one line Wire, in the track portion of the system.

Another object of the present invention is to provide a system on the lines above noted of such a nature that it may be applied to roads already equipped With the modern au tomatic block signaling systems Without requiring any change therein, or that will in anywise affect the reliability thereof.

It is further an object of this invention to provide a system of the foregoing described character, and such that by reason of the simplicity of its parts or units and the simplicity in the method of their organization or arrangement, there is secured a means that is not only correct in operative principle and that will afford the greatest degree of certainty and reliability of operation but that obtains these results at a minimum cost in power, apparatus and the maintenance of same.

To these ends the system is divisible'priniarily into two parts to wit:

First,The danger signal and train controlling apparatus, in which a closed circuit element thereof is mechanically operated by reason of the movement of a con act shoe, every time it encounters and en ages an unencrgized ramp, at predetermined points along the right of way.

Second,i%.n electrical equipment that comprises a simple type of engine carried partial circuit, an included transient control magnet, and a contact shoe, connected to form a conducting part of said circuit, when the shoe engages with ramp to complete a partial. circuit on the track, under the control of an all-rail track circuit.

The primary portions or units of the system, to wit, the closedvcircuit element and the engine partial circuit, are interconnected, under safety conditions, by a bridging loop through the movement of an armature lever of the transient actuator magnet, when the latter is active, to place thereby a low resistance shunt across the closed circuit element to afford a parallel pathway for said circuit that will be unaffected by the mechanical break later effected by the movement of the contact shoe.

A secondary or normally open clear signal working circuit car ied upon the locomotive or carrier is simultaneously closed by the movement of the armature-lever of the transient magnet when the latter is active, to produce a safety signal, while this last mentioned circuit is made to serve the purpose of energizing a retaining or holding magnet included therein to prolong the establishment of the circuit connections produced by the transient magnet. Said circuit is also made to serve by reason of circuit breaking magnet included therein, to cut off current in the transient magnet-the instant it has completed its functions.

/Vith respect to that portion of the system comprising the danger signal and train controlling apparatus, reference will be made to the circuit arrangements only in a gen eral manner, to wit; to the opening and closing of the control circuit A, that includes the danger signal and brake governing electromagnets 7 and 8, as the remaining portion of the system will be found fully described and illustrated in the type of system disclosed in United States Letters Patent,- Reissue No. 14676, dated June 24th, 1919,

and entitled Combined automatic train signaling and control systems.

the present invention does not relate to the structure of the operating mechanisms but only to the organization and coi'nbination of the aforesaid mentioned circuits for controlling and operating such mechanism, such means will be shown diagran'iatically.

In the accompanying h'awings, forming a part of the specification, Figure l is a disgramatic view illustrating the track-circuit sections for two adjacent blocks and shov. ing the train carried apparatus brought into operative relation therewith u der safety conditions, at a detcrniiinue pc such as at a signal and traffic controhii ramp,

which is preferably located within braking distance of a block unction.

Figure 2 shows in side elevation the train carried shoe structure Wlbll depending shoe in contact with a fragamentary portion of the ramp.

Like characters of reference indicate corresponding parts in the ligures, while the arrow shows the direction of traiiic for such an equipped line.

in the embodiment of the present invention as shown in Figure l, X and Y represent two block portions of normally closed all-rail track circuit sections, having similar track equipment. As is well understood the allrail track-circuit consists essentially of opposite running rails 0 o which serve as conductors and are defined at their block limits, respectively by insulated joints j, j or their equivalent. These running rails are connected across their advance ends by a source of electric energy T., while a trackrelay T. is connected across their rear ends.

R, designates a fixed roadside rail or ramp, the top surface of which presents at its entrance end an ascending incline and from its center to its eXit end a descending incline, preferably an eighth of an inch to the foot.

The ramp lt disposed parallel to the running rails and to one side thereof, and is connected by a line wire or conductor 'l. L. of low resistance, to the contact linger or armature a, controlled by the track-relay T. included in the all-rail track circuit section Y. so that the loop T. L. thus formed willbe controlled thereby to permit or prevent the delivery of current thereto by the engaging shoe of a passing locomotive, according to the safety or danger conditions in the block ahead.

The line conductor T. L. of the track loop or partial circuit may be placed on a pole line and in addition to its control the track-relay T. ll, it n1 be also open r and closed by the movement of the si nal blade (not shown) to thereby produce tvxo breaks therein under danger conditions.

by e 0 The movable contact shoe S which is suitably insulated from the locomotive structure, is adapted to co-operate with the ramp R and is arranged to depend in a suitable running position in line with said ramp, and owing to the vertical inclination of the latter, the shoe is adapted to be moved upwardly by reason of its traveling over the first half of the ramp and to be lowered by its travel over the other portion of the ramp, to thereby cause the actuation of the circuit breaker C B arranged as shown in operative connection with said shoe.

The movable contact shoe and circuit breaker mechanism is designed particularly to coact with the normally closed circuit A, in that type ol system shown, described and claimed in Reissue Patent No. 1et676, hereinbet'ore alluded to.

The members (Z and C" (see Fig. 2) of the circuit breaker C B are included as terminals in the loop Z, 1- that forms the exten sion of the circuitA, and when actuated by the lifting of shoes will open said circuit to cause the actuation of the danger signal and train control apparatus in accordance with the provisions shown described and claimed in Peissue Patent No. H676.

The mechanism just described is preliininarily adjusted to break said closed circuit portion A, every time the shoe encounters and travels over an unenergized ramp, by a direct and positive mechanical action, to produce danger signal and train control functions.

According to the plan of this invention it is proposed to act automatically on a distant train from a point which it is dangerous to approach, and at such a distance from the abnormal or occupied block as to provide an ample braking distance in which to bring trains under control. or to a stop, from the customary speeds. To this end the ramp R is therefore placed. from 11500 to 2300 feet back of the advance block junction. I

Under satety conditions, provision is made in this invention not only to determine such a condition in an advance track circuit section or block before it is reached and to indicate that condition by an appropriate clear signal in the cab of the locomotive but there is provided a means that will intervene totorestall the action that would necessarily follow the breakage of the loop portion Z, Z, of the closed circuit element A.., by the movement of the shoe in its engagement with and travel over the ramp ll.

To this end there is provided a low resistance shunt, orbridglng loops. 8., that is automatically inserted in the closed circuit element A, by reason of the action of a supplemental circuit means to be presently described, and this shunting is effected in point of time before the break occurs in the parallel pathway outside the limitsot' the shunt, occasioned by the movement and operation of the shoe.

The supplemental or safety circuit controlling means comprises a simple type of pick-up or detector circuit that consists of two parts, to wit:

One part of said circuit includes the track partial circuit including the ramp R, and line wire T. L., already described.

The other part of said circuit is shown as being carried by the locomotive or carrier and forms partial circuit thereon. that is made up of a conductor St (in full black line) and which may be traced follows:

For convenience this circuit will not be traced from the generator G, which supplies the current thereto, in the conventional manner but will begin preferably by tracing the electrical pathway thereof from the ramp R, and track loop T. L, through the movable contact shoe S, thence by conductor through the instrumentalities E., K., included in series therein to-one pole of the generator G, through the other pole connection and conductor 50 to the ground connection G., thence through the mass of metal of the locomotive to the wheels W, to the running rail r, back through the track loop T. L.

Normally when a locomotive thus equipped is running between signaling and traffic controlling points, the circuit thus traced re mains unenergized. If the track partial circuit is found to be open upon reaching a ramp, no delivery of current from the generator G, to the pick-up circuit will occur and the upward movement of the contact shoe acting upon the circuit breaker C B" will cause the production of a danger signal and the stopping of the train according to the workings of that portion of the system shown. and described in Reissue Patent No. 14676.

On the other hand under safety conditions, when the partial track circuit is found to be closed under the influence of the rail track circuit ahead, current will be delivered from the generator G, to the ramp R, to make responsive the electro-magnetic apparatus carried on the locomotive, which latter will be now described.

That portion of the pick-up circuit located on the locomotive includes an electromagnet, designated as the transient control or actuator magnet E, whose armature lever K is attracted to a control position, to synchronously close independent. circuit closers or supply contacts 7a, 7c,that of 70, serving to close the bridging loop or low resistance shunt a. hereinbefore described and for the purpose. intended.

The armature lever K, which constitutes a double acting circuit closer is properly insulated in those parts required to safe guard the supply contacts is and 7c.

The circuit arrangen'ients thus far described with respect to the supplemental circuit means depends upon the generator G, for curent supply, and it will be noted. that the pick-up circuit is connected in parallel to said generator with the headlight circuit which latter is made up of conductors ll C and elements L S. D S, CO and H re spectively.

The turbo-generator ordinarily employed to furnish current to the ele tric headlight may be safely made availal as a source of electric energy in the present invention, especially if the ground connection G, is automatically made (not shown) only when the Contact shoe is raised by reason of its engagement with the ramp, whereby no grounds are ordinai 'ly in existence.

The contacts Z: ween closed by the movement of the arn'iature lever l'il, serve to complete the l cal clear cab carried circuit, which includes the ii'ollowing instrumentalities and which may be traced as follows:

Leading to and in return from the storage sattcry 6 are conductors L, L", which are shown including fuses f, at suitable points. l designates an electro-magnet that is incl ded in series (coils thereof in parallel) with. circuit breaking magnet T. 1%., in said circuit.

As this circuit is primarily employed as a clear signal circuit, a low voltage incandescent lamp L, is included in with magnets ll and T. M.

lVhen this local circuit is closed the electro-magnets F and T. M. are energized and the clear signal is illuminated.

'A whistle may be also actuated by employment oi another magnet if desired, in said circuit.

According to the plan of this invention it is desirable and necessary to continue the illum ration of said lamp in and the ener- {I l ll ,n of the tl'liOl'Qatl-ltl GlGCtlf0-l1lti1i until the engineer" he takes appro firiatc action.

l.hoii1ii orc a reverse push-button P is izutluded in series with the otl .r instrumeni" i in said circuit, and this push button may he manually operated by the engineer to open said circuit, to cause the release of the armatures l5, respectively of the clcctroniagnets F and T M, and the e);- tinguishment of the lamp L.

The electro-nngnet pair F, included in the clear signal circuit just described serves as a retaining or holding means for the arn'iature lever K, when the latter has been attracted to a closed position by the transient control magnet E.

By referring to the drawings, Figure 1, it will be observed that the magnet pair F, is associated with the magnet pair that the ttllllittillfi K may he mounted to extend in proximity to both, to serve as a common armature, in such a manner as to be brought within the influence of the lield. of force of the cores of both pairs of magnets.

By reason of this arrangement, when the armature K is initially attracted by he magnet E, its continued relative movement of attraction is enforced by the action of the magnet 1 when the contact L has been made and upon reaching a predetermined point in its throw it will be retained in attracted position by said magnet l which will continue the necessary electromagnetic power required to hold said armature, after the magnet E, has become tie-energized.

The electro-magnetic circuit hreaker T included in the clear signal circuit in, serves as a trip magnet to break by reason of the movement of its attracted armature K, the pick-up or engine carried partial circuit, and this action of the cutting off of the current in the pick-up circuit follows the completed movement of the armature lever ll, of the transient control magnet E, occurring almost instantly thereafter, thereby utilizing the current from the head-light generator, for the purposes of this invention only tor the moment.

'l he armature ll. is counter-halanced to hold it normally in a circuit closing position. 7 I

From the foregoing described means it is apparent that under safety conditions, upon the completion of the picleup circuit through its track connections, which is obtained. the moment there is secured a substantial electrical contact of the movable shoe with the ramp, the transient control magnet E, will be energized to perform its duty of attracting the armature lever K, to close the control contacts 7c, 70, respectively, whereupon the former, when closed will serve to introduce the preventative low resistance shunt s s. in the manner described, while the lat tor or supply contacts 7:) will. be simultaneously closed to complete the clear signal circuit to permit it to perforn': its intended functions.

its the locomotive upon which the aforesaid apparatus installed may pass a ramp at a high rate of s )eed to cause the traveling shoe to be moved quickly to its upward limit of movement to actuate the circuit breaker C B and cause an interruption of the closed circuit element A, it will be found necessary in practice to employ means that will introduce a time control element into the workings of said apparatus, to insure a properly timed sequence in the relative introduction of the preventative shunt and the opening of the circuit breaker C B.

To accomplish this object in a simple fashion, the shoe- 5, is provided centrally with lowan upstanding stem 1' upon the upper extremity of which is mounted a striking or pusher disc I).

The circuit breaking device C B, which is mechanically operated by reason of the predetermined movement or throw of the pusher disc 5, comprises the following essential parts.

designates a stem that is adapted to slide or reciprocate vertically, in a stat-ionary support I), in alignment with the stem 1', and in opposition to the coiled spring S".

This stem r carries at its upper end the contact disc member 6 that is held normally' seat-ed against its complementary member CK, by the action of the spring S".

The stein 1' is provided at its lower end with a pusher disc 6 arranged coaxially with and in the pathway of the striking disc 6, but normally separated two or three inches therefrom.

By reason of such a construction and arrangement the lowermost disc b has to be raised a predetermined distance before striking the opposing disc 6 to unseat the contact disc and operate the circuit breaker C B to break the terminals of the loop Z, Z, upon the lifting of the shoe S Such an arrangement permits of the time allowance required for the throw of the armature K and the consequent insertion of the low resistance shunt s s to preserve the continuity of the closed circuit element A before the mechanical break is effected by the lifting of the shoe,-under safety conditions.

I claim-- 1. In a system of the character described, the combination with a closed circuit oper ating to stop a train by the breaking of said circuit, of a loopextension included in said circuit, a circuit breaker included in said loop, a contact shoe carried by the train for actuating said circuit breaker, a bridging 100p for completing the first mentioned loop to form a by-path, and an electro-magnet for opening and closing the last mentioned loop, a partial circuit carried by the train that terminates respectively in connection with said shoe and with a ground through the wheels of the train, a source of electric energy for said partial circuit, the first mentioned electro magnet included in said partial circuit, an armature for said electromagnet, that controls by its movement the bridging loop, a local circuit for holding the armature of said electro-magnet in att-racted position and for breaking said partial circuit, and a track mechanism consisting of a closed track circuit in each block, including a track-relay in the rearward end of each block, a local track loop at the forward end of each block through the track relay contacts at the block immediately in advance, and a ramp located along the right of way in the pathway for engagement with said shoe, said ramp being included in the track loop.

2. In a system of the character described, normally closed track circuits, a normally closed engine carried circuit operating to produce danger signals and to stop a train, a cont-rolling partial circuit carried on the engine that is between the track circuit and the normally closed engine circuit, the latter comprising an electromagnet and armature, a movable contact shoe for breaking the engine circuit and which forms a part of the partial circuit, a ramp arranged in the pathwc for engagement with said shoe along the line, a track loop controlled by atrack circuit a head connected with said ramp and running rails of the track-circuit in the rear of the controlling track-circuit, a local clear signal engine circuit operative when closed to produce a clear signal, and electromagnetic means included in the last mentioned circuit for locking the first men tioned armature in attracted position, and means also included in the last mentioned circuit for breaking the first mentioned partial circuit after the armature of the included magnet has been attracted and held and a means for manually opening the clear signal circuit.

3. In a system of the character described, the combination of a track divided into closed track circuit sections, a local partial circuit adjacent each track circuit limit that includes track-relay contacts in the advance section, a ramp and connection to the run ning rails in each section, a local partial circuit carried on an engine that is adapted to be completed by the partial circuit on the track and brought into operation when the latter is closed, an electro-magnet included in said engine carried partial circuit, an arn'lature. a movable contact shoe included in the last mentioned circuit and adapted to engage the ramp along the line, a normally closed engine circuit operated to produce a danger signal and to stop a train upon the movement of the shoe in its engagement with the ramp, a normally open clear signal circuit carried by the engine that is closed by the attraction of the armature of the first mentioned electro-magnet, means included in said clear circuit for interrupting the partial circuit upon the attraction of said armature and manually operated means for opening said clear signal circuit.

4@. In a system of the character described comprising an engine carried source ofelectrio energy grounded at one pole to the metallic body of the locomotive, a conductor connected at the opposite pole thereof, a movable contact shoe connected to the other terminal of said conductor, a local partial track-circuit adjacent to the track, a ramp for engaging said shoe and connected in series with the adjacent running rails to form said partial circuit, a local normally closed danger signal circuit carried by the engine and operated by the movement oi: the shoe, a normally open clear signal circuit carried on the engine, an electro-magnet and armature, the former included in the conductor connected to the source of energy, While the attraction of the latter brie ges the electrical. breakage of the danger signal circuit by the operation of the shoe and simultaneously closes the clear signal circuit, and a means included in the last mentioned circuit for locking said armature in an attracted posf v. and interrupting the current flow through said electro-niagnet, and a manually operated means "for opening the clear signal circuit.

5. In a system of the character described, the combination with a track divided into all-rail circuit sections, and a local partial circuit on the track connected to the running rails of a given block and including a ramp and controlled by an advance traclc circuit section, o1": a movable contact SACK, carried by the engine for engagement with said ramp, a transient inechan' sin roaipris' an engine carried partial circuit containin a transient electro-magnet and an armature controlled initially thereby, an e1 gine car ried source of electric energy for said partial circuit, a local engine carried danger signal circuit that is normally closed and that is operated by the movement of the shoe to produce danger signals and to stop t ne train and that is controlled by said armature when attracted to maintain said czcuit closed to negative the operative elliect of said shoe, an engine carried clear signal circuit closed by said armature, that in turn includes a magnet. by means oi which the armature is held attracted and said circuitcompleted and a circuit breaking maonet included in the last mentioned circuit for in terrupting the engine carried partial circuit and manual restoring means whereby the operator may open the clear s nal circuit and allow of the release of ti e armature of the transient electii'oniagnet.

in testimony whereof I atlii; my signal u re.

J'OieFH WHITMAN BUELL. 

